The need to exchange data between computers has never been greater. For example, new demands on traditional Point-of-Sale applications require immediate (near real time) sales data to be transmitted from retail stores to their central office. Electronic Data Interchange (EDI)'s goal of paperless electronic commerce between customers and suppliers requires that computers be able to exchange order and payment information 24 hours a day. And multinational corporations with offices around the world need to be able to exchange files, send faxes, and conduct voice and multimedia sessions with employees at any time of day for minimal cost.
Existing methods for exchanging data (including fax and voice) between two geographically distant computers or fax machines utilize (1) dial-up point-to-point connections over the Public Switched Telephone Network (PSTN); (2) dedicated transmission connections (also known as private lines or leased lines); and (3) dial-up data network connections, like the Internet. Method 1 requires one computer to initiate a data exchange with the other by using the PSTN to establish a long distance phone call during which the two computers exchange data. This Method 1 is cost effective for weekly or monthly exchanges of small amounts of data. However, it is undesirable for lengthy data transfers, due to the toll time charges associated with long-distance phone calls.
Method 2 utilizes dedicated transmission lines between two computers for exchanging data. For frequent exchanges of large amounts of data, Method 2 is more cost effective than Method 1 but typically requires a fixed monthly payment for the dedicated transmission line, regardless of the amount of data exchanged. As with Method 1, the computers are able to exchange data at any time, although dedicated transmission lines do not incur the overhead or delay associated with Method 1.
Method 3, using dial-up data networks, like the Internet, to transfer data, improves upon Methods 1 and 2 since there are (typically) no long-distance fees associated with connecting to the Internet. Another benefit is that Internet Service Providers (ISP) provide access to the Internet at rates significantly lower than the rates for dedicated transmission lines.
For two computers to exchange data over the Internet at any time, they must be connected to the Internet 24 hours a day or connected at predetermined times, or use a person at one computer to place a telephone call to a person at the other computer to tell him/her to become connected with the Internet. Unfortunately, when the data transferred is infrequent and/or small in size, the cost of 24-hour connection to the Internet can be greater than the costs associated with a direct point-to-point connection over the PSTN between the two computers. And connecting at predetermined times precludes the transmission of real-time or near real-time data and does not provide any flexibility, for example, if heavy data traffic slows the communication.
A more cost effective method would combine the best features of Methods 1 and 3 to allow data transfers over the Internet, but not require that both computers maintain a 24-hour connection to the Internet or rely on a predetermined connection schedule. It would be ideal if there were a way that both computers would automatically, without human intervention, be able to connect to the Internet only when data exchange is required so that connect-time charges would be kept to a minimum.